I would say its not supported if its not in portage. You can try the .9999 ebuilds in the overlay, but if you break our system you get to keep all the pieces.

Don't ever try to build packages yourself. Portage has all kinds of nifty little tricks for keeping track of everything that will break if you start manually installing stuff._________________First things first, but not necessarily in that order.

At first, those ebuilds will likely appear in kde overlay. No idea how long it will take, though._________________backend.cpp:92:2: warning: #warning TODO - this error message is about as useful as a cooling unit in the arctic